1. on the average (=on average, on an average) 平均
2. (be) aware of (=be conscious of , having knowledge or consciousness)意识到,知道.
3. at the back of (=behind) 在后面
4. in the back of 在后部(里面); on the back of 在后部(外面); be on ones back(=be ill in bed) 卧病不起.
5. at ones back(=supporting or favoring sb.) 支持,维护; have sb. at ones back 有支持, 有作后台
6. turn ones back on sb. (=turn away from sb. in an impolite way) 不理睬(某人),背弃,抛弃
7. behind ones back 背着某人(说坏话)
8. be based on / upon 基于
9. on the basis of 根据, 在基础上
10. beatat 在运动项目上打赢
11. begin with 以开始. to begin with (=first of all) 首先, 第一(经常用于开始语)
12. on behalf of (=as the representative of) 以名义
13. believe in(=have faith or trust in; consider sth./sb. to be true) 相信,依赖,信仰.
14. benefit (from) 受益,得到好处.
15. for the benefit of 为了的利益(好处)
16. for the better 好转
17. get the better of (=defeat sb.) 打败, 胜过.
18. by birth 在出生上,论出身,按血统 at birth 在出生时; give birth to 出生
19. blame sb. for sth. 因责备某人 . blame sth. on sb. 把推在某人身上
20. in blossom开花(指树木) be in blossom开花(强调状态) come into blossom开花(强调动作)
21. on board 到船上, 在船上, 上火车或飞机
22. boast of (or about) 吹嘘
23. out of breath 喘不过气来
24. in brief(=in as few words as possible)简言之
25. in bulk 成批地,不散装的
26. take the floor 起立发言
27. on business 出差办事.
28. be busy with sth.于某事 。 be busy doing sth. 忙于做某事
29. last but one 倒数第二.
30. but for (=without) 要不是. 表示假设
31. buy sth. formoney 用多少钱买
32. be capable of 能够, 有能力 be capable of being +过去分词:是能够被的
33. in any case(=for love or money, at any rate, at any price, at any cost, whatever happens; anyhow)无论如何
34. in case (=for fear that) 万一;
35. in case of (=in the event of)如果发生万一 in the case of 至于, 就而言
36. in no case在任何情况下都不(放句首倒装句)
37. be cautious of 谨防
38. center ones attention on(=focus ones attention on) 把某人的注意力集中在上
39. be certain of (=be sure of) 有把握, 一定.
40. for certain of (=for sure )肯定地,有把握地